Reproduction

The great majority of female A. mellifera in a hive are sterile workers. Only queens mate and lay eggs. Normally there is only a single reproductive queen in a hive.

During periods of suitably mild weather in spring and summer, males leave the hive and gather at "drone assembly areas" near the hive. Virgin queens will fly through these areas, attracting the males with pheromones. The males pursue, and attempt to mate with the queen in flight. Sometimes a "comet" forms, as a cluster of males forms around the female, with a string of other males trying to catch up. Each male who succeeds in mating drops away, and dies within a few hours or days. Males who do not mate will continue to loiter in the assembly areas until they mate or die trying. Queens will mate with up to 10 males in a single flight.

Queens may mate with males from their own hive, or from other hives in the area. The queen's mating behavior is centered around finding the best place to mate beforehand, by taking directional flights for a period of time, lasting no more than a couple of days. Afterward, she leaves the hive and flies to mate with drones in an assembly area. This normally starts to occur after their first week of birth. The queen does this up to four times. After this congregate of mating has occurred, she never mates again in her lifetime. (Adjare, 1990; Sammataro and Avitabile, 1998; Tarpy and Page Jr., 2000)

Apis mellifera queens are the primary reproducers of the nest and all of the activities of the colony are centered around their reproductive behaviors and their survival. The queen is the only fertile female in the colony. She lays eggs nearly continuously throughout the year, sometimes pausing in late fall in cold climates. A particularly fertile queen may lay as many as 1,000 eggs/day, and 200,000 eggs in her lifetime. It takes a queen about 16 days to reach adulthood, and another week or more to begin laying eggs. Males take about 24 days to emerge as adults, and begin leaving the nest for assembly areas a few days after that.

Queen honeybees can control whether or not an egg they lay is fertilized. Unfertilized eggs develop as males and are haploid (have only one set of chromosomes). Fertilized eggs are diploid (two sets of chromosomes) and develop as workers or new queens, depending on how they are fed as larvae. Queens may increase the ratio of male to female eggs they lay if they are diseased or injured, or in response to problems in the colony.

Healthy, well-fed honeybee colonies reproduce by "swarming." The workers in the colony begin by producing numerous queen larvae. Shortly before the new queens emerge, the resident, egg-laying queen leaves the hive, taking up to half the workers with her. This "swarm" forms a temporary group in a tree nearby, while workers scout for a suitable location for a new hive. Once they find one, the swarm moves into the space, and begins building comb and starting the process of food collection and reproduction again.

Meanwhile at the old hive, the new queens emerge from their cells. If the population of workers is large enough, and there are few queens emerging, then the first one or two may leave with "afterswarms" of workers. After the swarming is completed, any remaining new queens try to sting and kill each other, continuing to fight until all but one is dead. After her competition is removed, the surviving queen begins to lay eggs.

Normally the pheromones secreted by a healthy queen prevent workers from reproducing, but if a colony remains queenless for long, some workers will begin laying eggs. These eggs are unfertilized, and so develop as males. (Adjare, 1990; Milne and Milne, 2000; Sammataro and Avitabile, 1998; Tarpy and Page Jr., 2000)

As in most eusocial insects, the offspring of fertile females (queens) are cared for other members of the colony. In honeybees, the caretakers are sterile females, daughters of the queen, called workers.

Workers build and maintain the comb where young bees are raised, gather food (nectar and pollen) feed and tend larvae, and defend the hive and its young from predators and parasites.

Young queens inherit their hive from their mothers. Often several new queens emerge after the old queen leaves with a swarm to found a new colony. The new queens fight for control of the hive, and only one survives the conflict. (Adjare, 1990; Sammataro and Avitabile, 1998)